Relief valve



April 14, 1925"" 1 1,533,640

' F. C. FANTZ ET AL RELIEF VALVE I Filed ay 4,1921 2 Sheets-Sheet 1 gvwemtoza 35 WA Qu /ma? April 14, 1925. 1,533,640

J F. C. FANTZ ET AL RELIEF VALVE Filed y 4. 1921 2 Sheets-Sheet 2 N- 3 v R {Q a q" fdgiflgwtozg um, musa mm Patented l4, was.

rears also nowaaro "o.

souven r, or NEW YORK PATENT arms;

sum, or eon-'1: ARTHUR, 'rnxas'assrenons To a NZ'YH A. CORPORATION or TEXAS.

BELIEF vALvE.

application filed May 4,

' within limits.

One object of the invention isto provide a valve capable of opening and closing with an accelerated motion in orderto prevent ivirel ravving.

1n the accompanying idravvingsiveliavey Another object is to provide a valve capable of function fluids under high teu'iperatures. 4

Additional objects and advantages of the invention will be set forth in the following detailed description thereof,

illustrated a preferred form of the invention in WlliClTI- Figure '1 is an elevation of an apparatus roustructcd in accor(lance.with thoinvention. and constituting; an embodiment thereof. i

Figure 2 is a vertical %ction the line 2- 2 otl igure 1.

Figure 3 a diagram givenby ivay of example to illustrate certain principles of the invention.

In the drawings '10 designates a valve body and 11 a valve bonnet. The body is arranged to vbe mounted. in a vertical position and to form \vith'the bonnet an L fitting in order that fluids escaping Whenvthe valve is opened. may be discharged into a pipe 12- by which the fluids may he safely removedv A vided in. order to insure a gas tight joint between the body and the omiiiet.

A valve 14- is mounted Within the ,and a seat and m a guide for the valve are provided by means ofacage 15;t-he upper annular portion or which constitutes a valve C seat 16 and the depending Wings of ivhilh in, properly under hi gh v pressures and zulapted to discharge rapidly taken on packing ring 13 may be pro-\ 1921. Serial m. $66,858.

form. a guide for the lower part 17 of the valve so that the valve may be centered upon itsseiit. For the purpose of provid in the required buoyancy the valve is pref erably equipped with a projecting lip 18 extending around its periphery and with an intervening annular cavity 18*. The cage is equipped with threads by means of ivhich it may be attached to the body 10, a shoulder 19 being adapted 'to'fit into a recess in the body and'thus form a' tight joint.

The valve 14 is provided with a stem 20 which is arranged-to be placed in operative engagement with the valve in such a manner as will insure a flexible action between valve and stem. As shown in-the drawing the upper end of, the valve is hollowed out to form a cavity 21 communicating with which is a threaded opening 22. The lower end of the valve stem has a flange portion 23 externally threaded to engage thev threads 22.v In joining' the parts the valve stem is fiange portion is Within the hollow cavity .21 which base somewhatlarger diameter ereuee to the valve' .A yoke 24 is suitably mounted upon the f bonnet lljand the valve stem 20 is arranged -to pass through the wall of the bonnet and extend upwardly within this yoke. A boss ll is preferably provided to serve as a guide for the valvester'n. .The valvefstem is equipped with a stalling: box 25-, f v The stem is made with an enlargemen forming a shoulder 26 which,, upon the upward movement ofthe stem,- is adapted to be seated in ai-recess 27 located in the boss thus, serves'not only to limit the upward movement of the valve but-'to' protect the stuffing box 25 from the pressure exerted in the bonnet. 11 when the valve 14. is open. This featureis-especially desirable when usingth'e valve to relieve the-pressure 0 highly heated vapors and gases as the packing is shielded from the deterioratingaction of the hot rgases Tl1e, v'alve steni is provided with a crosshad 28 to which it maybe attached in any screwed .in-to the valve until the ring orthanthe threaded opening 22. thus giving; the valve-stern a' free movement with ref-' Theshoulder is adapted to for-1n a' tight/joint when seated in the recess 2 and {suitable rnanner, pairof arms 29 carry 6 the weighted I and the pins 33 and 34 may be secured with cotter pins 35.

Referring now to Figure 3 tion of the various forces acting through the toggle joints. as well as their points of application to the various links and levers will be given in order that the principle of operation of these elements be clearly under:

' stood the pressure j b-and 7) represent the 3034 of the :weights ."indi cated by lines 0 d and 0' action of forces In Figure 3, under the-valve acting vertically upward through the valve the crosshcad 28 is represented by the line (,1' atright angles to the "l and F denote theforees acting on each pin 33, respectively, the direction of these f recs being parallel to the force F and the n h'tgnitude of each'of which is equal to F a and (1 denote the crosshead pins 33: weighted arm pins 0 and 0- designate the fulcrum pins 31, and d and r denote the points of application 30 to the arms 29, whiclrare g respectively. In order to simplify the explanation the operating against only. one of the weighted levers 29 isvconsid e'red and to-render the description concrete itis assumed that the pressures up to Within the The diameter of the opening covered by the valve when seated is talten as 3 inches and, therefore, the-ar ais 7.06;) square inches. A pressure of 250 pounds per square inch on the flower surface of the valvegives approztimatelr a total force of 1770-pounds 250 pounds per square inch acting in an upwarddirection parallel to the valvestem. This force is'divided at the crosshead 28 and is transmitted to eaich'of the links 32 as a force of 885 pouudts,,F and F, acting in a direction parallel to the force F. It is to heunderstood tliat in the calculations given herein no accottht is taken of friction. I

When the valve is closed a ,line drawn through points- It and 5 forms the angle a: with the line 911 By. computation this angle is found to be 20 11' 46". force F acting on the line gu. is 885 pounds the resulting force ff directed along-the line a?) is calculated to be 944 jecting the line a?) mg a perpendicular 0a to the line point '0 which will pass throu 'h the-point 0, the turning moment of the one f about an explana- F represents the force of stem 20;

line of force F;

-.Point 7) now occupies valve isdesigned to hold vessel to which it is connected.

the

Since the 1 pounds. By pro-; to the pointc and erect-j In order to determine the weight. W re- "'quired at the point (1 to balance aturmng moment of 1.711 inch pounds ,at thepoint o. the length of ad is assumed to be 15 inches it is found that W:114 pounds, or in other words that with a weight of 114. pounds on the arm 29, positioned 15 inches horizontally from point 0, a pressure of 250 pounds per square inch would he maintained under the valve. It is to he noted that the line abc is not at right angles to the line 0d; however, if the force f (944 pounds) were applied at. right angles to the lever 0d at a dis tunes from the pointo equal to 00 the same weight would be required to balance the force. The weight WV acts in a direction parallel and opposite to the force F, and, therefore, perpendicular to the line oecl'd'. ten the pressure under the valve rises above 250 pounds the opposing force of the weight W is overcome and the point a moves along the line ya until it reaches th point a. which is the limit of its travel. luring themovenient ofthe point a, the point 6 travels along the are be being restricted to that path by the fact that the length of the line 0/; remains constant, and 0b equals o'b. position b and the original angle at between the lines (1?) has been increased to angle .1," *tween the lines ya and ab'. The magnitude of the angle a." is calculated to be 3Q and as it is thus greater than the angle .2, the force, acting on the line ab is greaterthan the force f acting on the line ab. The force F remains 88 5 pounds, but the force v acting on the line ab, is found to be 1022 pounds. 'lheperpe'ndicular c'0- erected on theline a'b' is the length of the moment arm of theforce f"' acting about the point 0. It is foundjto be 2 inches in length. Therefore, the turning 'moment of the force 7 about point 0 is equal to f mac or 2044 inchpoundsn It obvious that the force now acting on the lever 29 isgreater than that actin onit when the valve-was closed. It woul',v therefore, require a heavier weight or under the valve when he placed 18 incheshfrom the center 0-in force acting on the valve. We thus have a condition in which the'movement of the levers, during the open-- ing of the valvehas increased force of a, and

is' found that the weight of 114 pounds'must lutl 15 iength c the npwsrci thrust of ihe voivo stem in has reiation' to the force applied to the Weightarm by the Weight W, sithongh the pres sure acting on the nndersiric oi the valve a may regarded as deems-sing Whiie the valve remains ope-n. The quick action of he vnivo is fine part" to this ii'icrenso "the upward 'ioi'cc aci'i against; i'hc "weight ed firms.

in order to ciesrij' iiinsiirste i'lhe princi pies involved it is necessary to consider the manner in which the length oi the iin'e 06' (which represents the moment arm when i'i'ic valve is closed) is increased to he Whenthe vaivc is open. The in crease is due to the for that the point '15 moves on the arc be about the point 0 on a line which does not pass through the center 0. The rehztive lengths of the lines 0]), 0b and the position of he center 0 in re- 'spect to the iine qa, ore such to the speed at which the mechanism operates afifiir it has once storied iron o store oi rest By noting the position of points (Z, d and (2" it will be seen than; the cenier oi grhwity of the weight W does not move through a straight line, as through dd oi" but instead moves along the are 650? d. As the distance 002" is' greater than 055', ii:

is obvious that the moment arm. and fore. the turning momenc of the Weight W about the point 0 is grestcse when the point d is reached and 5km, when 0 is reoched the length. of the momenr srm is egsin equal to ad. The --riiiicrcnce in length. however, of the moment arms on? and no? is so smoii as to require a dccressqfigni only 1.6 pounds in the weight W st o. to equal the origi nei turning moment a'ifihe point cZ. As this m difference is relatively smoii it may be dicregarded and the Eng'aiong the straight line do? (5, its turn; Eng rnon'lcm'i ai'onsyant. Thus she 'oniy appreciobie varia- 15 i on in magnitude 0% the forces acting; on c fever are caused by the change m the inngth of the moment arm from 00 to 00 mid the increase from force ,1? to ,1 The increase in fife force exerted; egai eigh; ii piece as; a. definite wirh L'Q opening of the rebound is such thee 1....e ratio of the force f to weight is ggresier than that of force to Weighi; V When Weighs is in ics uppermost position is fourui that the force f exerteci 211021;; "the iine Mo; when sngiie :1 3G" :nnmnii-s to pounds. The opposing from-91F m'iinp; along the line go found to he Hf? pounds. Th'

orce of MO pounds is required to'beiunco the Wcighvr, W in its xmpsrmost position, and is less than the original rorce, F" poumis), necessary toopen izhe vsive, due to the ioct thst the moment arm on for the upper position is longer thou 0c therefore requires a.

, there (reached the valve Wiii Weight considered niov:

being, therefore, considered as seiiiing; the opening "in the cycle oi? o crzition lower force an orotiuce the some turning momcntohowh toe point 0.

7.0691 pounds per square inch. (approximately), which is the pressure; under the valve which Wiii keep it open when rho weighted arms are in the uppermost position. When the pressure cirops below ibis point the turning 5 moments of the weights about ihe points 0 and 0 overbaisnce the'turning moments of the forces acting through the crosshcmi' and links and the Weights drop moving the valve inward; a. closed position. In the downward movement the length of the arm 00 is being decreased to its original length (/0 and the point 2) moves along the are be" and assumes its original position b. The angle .22 is also reduced by the some movement to angle m, decreasing iahe force f to f. fiince the force of the Weight remains procticoiiy constant and as iismegnitude in relation to the force f" increases until it is only acting against the force) there is s tendency to accelerate the closing mm/iemenb of: the veive. i

in operation when the predetermined pressure, for which 'the valve is set, is be moved 0H its sea-t and if it; constructed with the projecting hp 18 an caviiy 18, by which the effective areeocteci'on by the pressure ofythe coutoineri fluids is increaseci, there is a. hem dency to acceie'rafe the upward movernenc of the valve. This increment" is further ecceleraterL. by the lever arrangement by which, asthe valve moves upward, the force" acting upon the Weighted arms 29 is progressively increased. The result is that the valve pops oii its scaiv and reaches thev upperextremity of its travel in one quick movement When the pressure has been re aluced 21' gn'erietcrmined amount the Weighted arms force the who downward and by roasouoi ihe relative progressively increasing force oxeracd by the "weighted {Li-ms the who -forced into close contact with its and thereby prothe critical point of the valve. The wiveoi' onr'invencion is erticuiariy adapted as a, safety valve on stills wherein hydrocmi oiis are iistiiied'under pressure inesn'mch *the quick opening and 150 closing of tin: uivo prevents deposition of carbon between the valve and its seat anti cfiectuoily eliminates wire-(h-awin Apparatus of preferreriform and C911? struction has been illustrated and described venting; WiI'Er(iTiL\Vi'l1g oi;

for the purpose of showing: a way in which this invenoion may be usci but the inven- "tivcthought upon which the application is 

